The bending of conduit requires a way to insure that the bend is in the same plane as the rest of the conduit, i.e., does not form a dog-leg. Moreover, it is equally important to have a device which accurately measures the angle of the bend.
Previous devices have tried to provide these dual functions. For example, the patent to Yakkel, U.S. Pat. No. 4,274,208 discloses a precision bend level which contains a plane indicating level and angle indicating level. The plane indicating level, however, requires that it be attached to the conduit and then the conduit be rotated in the bending machine so as to reference the bending plane to level. Furthermore, the angle indicating level is not adjustable between multiple bend angles and is further not able to be referenced to a plumb position to compensate should the conduit itself or the bending machine not be level.
The patent to Morree, et al., U.S. Pat. No. 4,394,799 discloses a plane and angle indicating device. This device, however, also requires that it be attached to the conduit and then the conduit be rotated so as to reference the bending plane to level.
It is apparent, therefore, that no device has yet provided both a bending plane indicator and angle indicator, each of which may be set to a reference zero without adjusting the conduit or the bending machine. Moreover, no device has yet offered these functions while also being able to precisely measure any angle of bend.